Implement CoMPAS plugin list to Open-SCD-Core

[Stef3st]

Once Open-scd-core is in place, its possible to create your own official/default plugin list for your distribution. This means that Compas-Open-Scd can also implement its own list (can be found at /public/js/plugins.js). For now Compas-open-scd uses the Plugging mixin to load this file, which is basically a copy of the Plugging mixin from Open-scd. This will no longer be necassary.

Acceptance criteria:

• Make sure that the plugins list from compas-open-scd get loaded with open-scd-core
• Remove the Plugging mixin from compas-open-scd
• Remove additional files that will be unnecassary
  • CompasPlugging.test.ts
  • mock-compas-plugger.ts